The purpose of this article is to show through an interactive learning object (ILO) and the use of mathematical software GeoGebra how differential calculus can contribute as a principal basis for the understanding of financial formulas. To realize this, an ILO was developed, where the financial formulas are applied like: the present value, the net present value and the internal rate of return, used in the assessment of investment alternatives. These formulations are interpreted with the basis of differential calculus, where in a Cartesian plane are defined the variables and which parameters will be windows in the ILO.